Ether of Orbifolds

The orbifold lattice has been proposed as a route to practical quantum simulation of Yang–Mills theory, with claims of exponential speedup over all known approaches. Through analytical derivations, Monte Carlo simulation, and explicit circuit construction, we identify compounding costs entirely absent in Kogut–Susskind formulations: a mass-dependent Trotter overhead that scales as $m^4$, non-singlet contamination that grows as $m^2$ and worsens with penalty terms, and a mandatory mass extrapolation. Monte Carlo simulations of SU(3) establish a universal scaling: the continuum limit forces $m^2\propto 1\mathrm{/}a$, binding the Trotter step to the lattice spacing through a cost unique to orbifolds. For a fiducial ${10}^3$ calculation, the orbifold is ${10}^4$–${10}^{10}$ times more expensive than every published alternative. These results indicate that the claimed computational advantages do not at present survive quantitative scrutiny.